RESEARCH COMMUNICATIONS
Terrain response to the 1819 Allah
Bund earthquake in western Great
Rann of Kachchh, Gujarat, India
M. G. Thakkar1,*, Mamata Ngangom1,
P. S. Thakker2 and N. Juyal3
1
Department of Earth and Environmental Science,
KSKV Kachchh University, Bhuj-Kachchh 370 001, India
2
Space Applications Centre, Indian Space Research Organisation,
Ahmedabad 380 015, India
3
Geoscience Division, Physical Research Laboratory,
Ahmedabad 380 009, India
We report here the development of a drainage network following the 1819 Allah Bund earthquake in the
western Great Rann of Kachchh. The juvenile nature
of the drainage network, particularly along the scarp,
indicates that earth surface processes have not yet
attained equilibrium with the base level even after 200
years. Hence it serves as an ideal model of resurrection of topography dominantly controlled by the tectonics. Another important observation has been the
identification of a submerged/subsided tax collection
port around 60 km southwest of Sindri. Optical dating
of pottery indicates that the subsidence is coeval with
that of the Sindri fort. This would imply that during
1819 there were two subsiding areas separated by a
marginally high land mass (Sunda high). In the absence
of detailed structural data, a preliminary inference
has been drawn based on field and satellite data. It
suggests flexure folding of the footwall during the
1819 earthquake.
Keywords: Allah Bund, Basta Bunder, coseismic subsidence, drainage network, terrain resurrection.
THE Kachchh rift basin is passing through the rift reversal
phase in response to the compressive stresses active on
Indian plate1. The salt-encrusted terrain known as Ranns
of Kachchh are recent depositional basins within the
structural depressions resembling half graben formed during the later phase of uplift2,3. The Ranns existed as a
shallow embayment and inlets of the sea from the Tertiary until Recent4–6. Nevertheless, in the last 2 ka, silting
of the area, probably accompanied by elevation of the
land has converted the marine embayment into dry saltcovered mud flats slightly above the tidal range of
the Arabian Sea7. The present observations pertain to the
geomorphological changes that have occurred after the
1819 earthquake in the western Great Rann (Figure 1).
We have attempted to find a mechanism that could be
responsible for regional topographic changes in a single
earthquake of large magnitude in intra-plate settings and
the response of erosion over the rejuvenated landscape.
*For correspondence. (e-mail: [email protected])
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There are historical evidences to suggest that the Great
Rann witnessed moderate to strong earthquakes. For example, earthquakes of AD 893 and AD 1668 were reported
to be severe, which occurred to the north and northwest
of the Great Rann in Sind area, Pakistan8,9. Their impact
on the terrain morphology is still uncertain. Compared to
this, the 1819 Allah Bund earthquake estimated to be of
Mw 7.9 that occurred within the western Great Rann,
uplifted the 80 km long and 16 km wide region of the
Rann8,10–12. It has uplifted the Rann sediment to variable
heights (3–6 m) and obstructed the Nara River till 1826
(refs 9 and 11). Besides causing large-scale devastation in
the Kachchh region, a coseismic Sindri depression was
created against the uplifted land mass which led to the
submergence of the Sindri fort9 (Figure 1). During monsoon, the depression is inundated by sea water pushed
inland by the storm-induced tides of the Arabian Sea
from the west and southwest. Frequent inundation and
evaporation led to the formation of vast salt-encrusted
land masses10,13. The only detailed description on the
post-1819 earthquake-induced landform changes was
attempted by Rajendran and Rajendran9 with emphasis on
the scarp morphology and seismically induced deformations.
In this communication, we have studied the evolution
and modification of the drainage network in the vicinity
of Allah Bund scarp and ascertained the regional impact
of the 1819 earthquake, particularly on the less studied
southwestern part, viz. the Kori Creek area (Figures 1 and
2). Carless14 surveyed the area between Koteshwar
and Lakhpat and concluded that compared to the mainland
Kachchh, the Kori Creek (deltaic area) was depressed after
the 1819 Allah Bund earthquake. He also mentioned two
ruined forts; one proximal to Lakhpat was attributed
to the 1819 earthquake, whereas the other lying at the
western bank of Kori Creek called the Basta Bunder was
destroyed prior to the 1819 earthquake. A systematic
study is warranted in the Kori Creek that lies ~60 km
southwest of the Sindri depression to understand the style
of deformation and extent of the 1819 earthquakeinduced landform changes (Figure 1).
The south-facing Allah Bund scarp owes its genesis to
the north-dipping thrust that was activated during the
1819 earthquake9,15,16. The northern hanging wall is
dominated by young gullies and ravines, whereas the
southern footwall is frequently occupied by marine
ingression during monsoon (Figure 2). Some of the streams
follow the regional tilt (towards north), but majority of
them tend to incise the uplifted scarp in order to meet the
Nara River bed. The Nara River has attained the local
base level of the Sindri depression over the last 200
years. Compared to this, the juvenile streams are still in
the process of attaining the equilibrium profile of the
1819 uplifted terrain. Further, based on the headward
extent of incision, we could demarcate the northern limit
of coseismic uplift, which seems to vary between 3 and
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Figure 1. Location and physiographic map of the study area showing a part of the western Rann of Kachchh that was affected by
the 1819 Kachchh earthquake and generated large-scale coseismic features that modified the topography of the Rann and the western creek area of Kachchh. Note a channel of Indus known as Nara River abuts at the coseismic uplift of Allah Bund. Sunda is an
upwarped region between two coseismic depressions of Sindri in the northeast and Basta Bunder in the southwest.
13 km (Figures 2 and 3 b). Our indirect estimate based on
the extent of headward erosion compares well with the
levelling survey data of Rajendran and Rajendran9, but is
at variance with the estimate of the 16 km wide zone10,12.
The dominant northward tilt is also seen in the sediment
strata exposed near the Nara River channel (Figure 3 a).
We also performed the drainage density analyses,
which are used as a surrogate for terrain maturity/youthfulness. The drainage density is usually low in the arid
and semi-arid regions17. Therefore, in principle, a terrain
like the Great Rann should have low drainage density.
Instead, we observed moderately high density (14 km/km2)
around the Allah Bund scarp region, implying that the
terrain was rejuvenated in the recent times. We also observed few scarp-parallel drainages flowing from east to
west along the scarp crest (Figure 2). Such anomalous
deflection of the stream course has been attributed to the
high rate of structural uplift relative to erosion rates. In
such cases, transverse rivers tend to deviate the rising
land mass rather than cutting across it18,19. Sediment inciCURRENT SCIENCE, VOL. 103, NO. 2, 25 JULY 2012
sion rate is governed by the base-level change caused due
to climate and tectonics20. Assuming that during the last
200 years rainfall has not changed from the present-day
rainfall21 of 200–380 mm, the incision would largely be
governed by the tectonically induced relief changes.
Since the optical and radiocarbon ages22 of the uppermost
incised Rann sediment are around 2 ka years, we assume
that incipient drainage incision was largely after the 1819
earthquake around the scarp. Thus, we consider that the
observed incision happened during the last 200 years,
which is around 100 cm, i.e. around 0.5 cm/yr. This appears
quite high as the streams are yet to attain the local base
level, implying that in a tectonically active terrain, incision
probably is an ongoing process like Himalaya18.
Archaeological evidences suggest that the western
Great Rann was a hospitable terrain in the past14,22. Sites
proximal to the streams that were flowing into the Great
Rann from the Indus floodplain were being meticulously
selected by the historical people. Near Karim Shahi, the
archaeological site dated to 3000 yrs BP and now located
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Figure 2. A close view of the topographic expression of coseismic uplift of Allah Bund illustrates juvenile streams flowing to the north
from the gullied surface of the Allah Bund ridge and merging with the northern bet zone, while Nara River, a distributary of the Indus
flows to the south on the pre-1819 slope. Note the zone of defunct channels in response to the 1819 coseismic uplift to the west of Nara.
Figure 3. a, North-dipping uplifted Rann sediments near the northern margin of the Allah Bund uplift axis. This is a major channel of Nara that
incises the Allah Bund surface intermittently during major flooding in the north. b, Southwest-facing view of juvenile Rann surface marked in
Figure 2, showing distinct embryonic gullies against the Sindri depression.
proximal to the line of present-day tidal inundation22 is
not a favourable location for human habitation. That is
because historical evidence suggests that prior to the
1819 Allah Bund earthquake, large tracts of land NE of
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Kori Creek were above high tide level. After the 1819
earthquake, the terrain north of Kori Creek seems to have
subsided by about 1–5 m, leading to the creation of the
Sindri basin23. The archaeological site is located towards
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the northern margin of the subsided Sindri basin. Hence,
we attribute its present elevation to the coseismic subsidence caused during the 1819 earthquake.
Another major observation was the identification of the
ruined fort first reported by Carless14, called the Basta
Bunder, located ~25 km northwest of Koteshwar across
the Kori Creek (23°51′44.44″N, 68°30′16.36″E; Figures 1
and 4 a). The ruins of the fort are preserved in the form of
pentagonal walls protruding 20–40 cm above the tidal
mud flat of Padala Creek (Figure 4 a). The ruins get
flooded during spring tide. The preserved wall structure
indicates that the fort was made up of polygonal, fivewalled structure consisting of six bastions and one gate
5 m wide in the western wall. The northern wall was
longest (96 m) with kiln-like structure in the middle; the
eastern wall was 76 m long with a bastion of 10 m diameter; the southeastern wall was 33 m long with two
bastions of 10 and 12 m diameter at each end. The southern wall is completely collapsed, however a linear (92 m
long) stone foundation with cut bricks can be seen, join-
ing the SW bastion that is 20 m in diameter (Figure 4 b).
The dimensions of the bastions and gate, thickness of the
walls suggest that it was a robust structure comparable to
its modern counterpart at Lakhpat. Carless14 attributed its
destruction to a pre-1819 earthquake event whereas
Lylle13 suggested that it was destroyed during the 1819
coseismic subsidence that lowered it to the range of high
tide (Figure 4). The optical date obtained on the potsherd
collected from Basta Bundar gave an age of 214 ± 20 yrs.
Within error, the age broadly correlates with the 1819
earthquake and supports the suggestion of Lylle13. We attribute its destruction to the coseismic subsidence along
with the Sindri fort after the 1819 earthquake. In view of
this finding, we hypothesize that there was a complex
subsidence mechanism involved during the 1819 earthquake. There were two major subsidences (Sindri in the
NE and Basta Bunder in the SW) separated by a marginal
uplift around Sunda (Figure 1). The above deformation
can be explained by invoking a SW to NE (oblique)
compression (along two points A and B in Figure 1).
Figure 4. a, Satellite photograph of the location of Basta Bunder within the tidal mud flats of the western Kachchh Creek zone (inset). The
dimensions of six bastions and lengths of pentagon-shaped geometry of the fort walls at the bank of the Padala Creek are also shown. b, Remains of
fort wall elevated only a metre from the tidal mud flats. Note the wall is mostly made up of yellow-coloured Tertiary limestone locally available
near Lakhpat.
Figure 5. Schematic diagram of a cross-section from Allah Bund to Kori Creek (points A to B in Figure 1)
showing a major coseismic uplift of Allah Bund accompanied by subsidiary buckling of Sindri depression and
Basta Bundar subsidence separated by the Sunda uplift.
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This would have caused flexure buckling near the thrust
plane (Sindri fort subsidence), while upwarping southwest of Sindri caused the Sunda high and downwarping
towards the southwest caused the Basta Bunder subsidence (Figure 5). This is only a preliminary interpretation; a detailed structural analysis is in progress.
Our preliminary observations in the western Great
Rann indicate that the earth surface processes are in the
embryonic stage. We have not mapped the lateral variability of the 1819 scarp, but field observations indicate
that it was not more than 4 m. Considering the work of
Rajendran and Rajendran9, we have no estimate of how
much scarp height was inherited from the older event.
The study suggests that even in arid and semi-arid areas
one can have high juvenile stream concentration provided
the terrain is tectonically active. Assuming that majority
of the streams emerged after the 1819 earthquake (a reasonable assumption considering the stream morphology
and location), significant incision was observed, which
we attribute to the relief factor. Our study shows that
there was coseismic subsidence concurrent with the Sindri fort in the areas around the Kori Creek that led to the
submergence/subsidence of Basta Bunder. We suggest a
flexure buckling of silty clay-dominated Rann sediment –
a hypothesis that needs to be verified. The study provides
a renewed stimulus for carrying out detailed morphotectonic study in the western Great Rann for a better understanding of one of the major earthquakes and its impact
on the earth surface processes.
1. Biswas, S. K., A review of structure and tectonics of Kutch basin,
western India, with special reference to earthquakes. Curr. Sci.,
2005, 88, 1592–1600.
2. Biswas, S. K., Regional tectonic framework, structure and evolution of the western marginal basins of India. Tectonophysics,
1987, 135, 307–327.
3. Biswas, S. K., Note on the geology of Kachchh. Q. J. Geol., Min.
Metall. Soc. India, 1971, 43, 223–236.
4. Biswas, S. K., Basin framework, palaeoenvironment and depositional history of the Mesozoic sediments of Kachchh, Western
India. Q. J. Geol., Min. Metall. Soc. India, 1981, 53, 56–85.
5. Merh, S. S. and Patel, P. P., Quaternary geology and geomorphology of the Rann of Kutch. In Proceedings of the National Seminar
on Recent Quaternary Studies in India (eds Patel, M. P. and Desai,
N. D.), M.S. University of Baroda, Vadodara, 1988, pp. 377–391.
6. Merh, S. S., The Great Rann of Kachchh: perceptions of a field
geologist. J. Geol. Soc. India, 2005, 65, 9–25.
7. Glennie and Evans, G., A reconnaissance of the Great Rann of
Kutch, India. Sedimentology, 1976, 23, 625–647.
8. Oldham, T., A catalogue of Indian earthquakes from the earliest
time to the end of AD 1869. Mem. Geol. Surv. India, 1883, 19,
163–213.
212
9. Rajendran, C. P. and Rajendran, K., Characteristics of deformation
and past seismicity associated with the 1819 Kutch earthquake,
northwestern India. Bull. Seismol. Soc. Am., 2001, 91, 407–426.
10. Burnes, A., Memoir of the eastern branch of the River Indus, giving an account of the alterations produced on it by an earthquake,
also a theory of the formation of the Rann and some conjunctures
on the route of Alexander the Great; drawn up in the years 1827–
1828. R. Asiatic Soc. Trans., 1835, 3, 550–588.
11. Oldham, R. D., The Cutch (Kachh) earthquake of 16th June 1819
with a revision of the great earthquake of 12th June 1897. Mem.
Geol. Surv. India, 1926, 46, 71–146.
12. Baker, W. E., Remarks on the Allah Bund and on the drainage of
the eastern part of the Sind basin. Trans. Bombay Geogr. Soc.,
1846, 7, 186–188.
13. Lyell, C., Principles of Geology; or the Modern Changes of the
Earth and its Inhabitants, John Murray, London, 1850, 8th edn,
pp. 441–445.
14. Carless, Memoir to accompany the survey of the delta of the Indus
in 1838. J. R. Geogr. Soc. London, 1838, 8, 328–366.
15. Rajendran, C. P., Rajendran, K. and John, B., Surface deformation
related to the 1819 Kachchh earthquake: evidences for recurrent
activity. Curr. Sci., 1998, 75, 623–626.
16. Bilham, R., Slip parameters for the Rann of Kachchh, India, 16
June 1819 earthquake, quantified from contemporary accounts. In
Coastal Tectonics (eds Stewart, I. S. and Vita-Finzi, C.), Geological Society London, 1998, vol. 146, pp. 295–319.
17. Horton, R. E., Erosional development of stream and their drainage
basin: hydrophysical approach to quantitative morphology. Geol.
Soc. Am. Bull., 1945, 56, 275–370.
18. Seeber, L. and Gornitz, V., River profiles along the Himalayan arc
as indicators of active tectonics. Tectonophysics, 1983, 92, 335–
367.
19. Gupta, S., Himalayan drainage patterns and the origin of fluvial
megafans in the Ganges foreland basin. Geology, 1997, 25, 11–14.
20. Schumn, S. A. and Brakenridge, G. R., River responses. In North
America and Adjacent Oceans during the Last Deglaciation: Boulder, Colorado (eds Ruddiman, W. F. and Wright Jr, H. E.), Geological Society of America, Decade of North America Geology,
1987, vol. 3, pp. 221–240.
21. Pramanik, S. K., Hydrology of the Rajasthan desert: rainfall,
humidity and evaporation. In Proceedings of the Symposium on
Rajputana Desert, Natn. Inst. Sci. India, Delhi, 1952, pp. 183–197.
22. Tyagi, A. K., Sukhla, A. D., Bhushan, R., Thakker, P. S., Thakkar,
M. G. and Juyal, N., Mid-Holocene sedimentation and landscape
evolution in the Western Great Rann of Kachchh, India. Geomorphology, 2012, 151, 89–98.
23. Wynne, A. B., Memoir on the geology of Kutch. Mem. Geol. Surv.
India, 1872, 9, 1–294.
ACKNOWLEDGEMENTS. Financial assistance from the Department
of Science and Technology, New Delhi to M.G.T. (DST/SR/S4/ES-TG/022008) is gratefully acknowledged. We thank BSF-DIG, Bhuj and
Gandhinagar for permission to move around in restricted areas, and the
‘Crocodile Commandos’ of the Marine Wing of BSF at Koteshwar for
their help to reach Basta Bunder.
Received 20 December 2011; revised accepted 14 June 2012
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